1. Field of the Invention
This invention relates to a method of recording data, and particularly to a method of recording video data and accompanied sound data on a magnetic tape through a helical scanning.
2. Description of the Prior Art
A method of recording video data and accompanied sound data on a magnetic tape through a helical scanning is known. In such a method, each of helical scanned tracks includes a first recording area for the video data and a second recording area for the sound data, wherein the second recording area is extremely narrower than the first recording area because an amount of the video data is larger than that of the sound data. Particularly, in the case of recording an extremely fine image signal, such as HDTV (high-definition television) signal, the recording area of the sound signal is extremely narrower than that of the video signal. Such a sound signal is recorded at substantially the same position of respective tracks and the recording areas of the sound signal on consecutive tracks are arranged with a small width on the magnetic tape in the feeding direction of the magnetic tape.
Moreover, in the track pattern of the digital VTR mentioned above, a number of editing gaps (for example, IBG (Inter Block Gap), Preamble, Post amble, or the like) for rewriting of the video signal or the sound signal for editing are provided on each track.
FIG. 7 is an illustration of a prior art track format according to D2 format (NTSC). In this track format, the sound data is recorded upper and lower portion of respective tracks and there are edit gaps are provided for editing to reduce an affection of a timing error. These editing gap decreases the efficiency of utilizing the magnetic tape.
Further, the sound signal is recorded with every track-channel exchanged, so that there is an affection to other tracks such as unerasing or excessive erasing and the control is also complicated. Moreover, because the recording areas of the sound signal on respective tracks are mainly arranged in the feeding direction of the magnetic tape, there is a tendency that a burst error occurs due to a scratch in the longitudinal (horizontal) direction of the magnetic tape.